The invention relates generally to a hollow door construction employing a structural void filler for augmenting door strength. More specifically, the door panel herein includes a "honeycomb", multi-cellular void filler utilizing variable cell size to provide greater door strength than known prior art constructions.
Applicants are aware of the following references generally pertaining to door, or panel construction: U.S. Pat. Nos. 2,765,056, 10/02/56, Tyree; 2,824,630, 2/25/58, Tolman; 2,827,670, 3/25/58, Schwindt; 2,833,004, 5/06/58, Johnson et al.; 2,980,573, 4/18/61, Clifford; 4,130,682, 12/19/78, Lauko.
These references disclose a consistent or repeated cell configuration throughout the structural void filler. The Schwindt patent discloses and discusses a preferred construction using a higher concentration of cellular material in the vicinity of the longitudinal edges of the door, but this is accomplished by compressing the uniformly sized cells into a smaller volume than the remaining cells. As will become more apparent from the detailed description of the invention, the purpose, placement, and manner of accomplishing variable cell size in Schwindt is far removed from similar considerations of the invention herein.
Reference is also made to U.S. Pat. No. 4,372,717, issued to us on Feb. 8, 1983, disclosing a cellular void filler particularly adapted for filling voids within a container carrying articles of freight. This patent discloses a honeycomb cell construction designed to be manually expanded from a flat stack of strips into a relatively thick, structural void filler. The patented structure is further adapted to maintain an expanded configuration when freely suspended under its own weight. It is not directed towards a thin, rigid door panel construction designed for hinge suspension from a longitudinal frame edge.